Combustion device for hydrocarbon fuel



Dec. 21, 1965 R. w. KEAR ETAL COMBUSTION DEVICE FOR HYDROCARBON FUEL 2Sheets-Sheet 1 Filed Feb. '7, 1963 FIG! INVENTORS'.

ROBERT W. KEAR ALAN H. LANCASHIRE THEIR ATTORNEY Dec. 21, 1965 R. w.KEAR ETAL COMBUSTION DEVICE FOR HYDROGARBON FUEL 2 Sheets-Sheet 2 FiledFeb. 7, 1963 h m w \x A K FIG. 2

FIG. 3

INVENTORS'.

ROBERT W. KEAR ALAN H. LANCASH IRE THEIR ATTORNEY 3,224,679 CUMBUSTEUNDEVICE FOR HYDROCARBQN FUEL Robert W. Kear, Fetcham, and Alan H.Lancashire, Crowthorne, Berks, England, assignors to Sheil ()il Company,New York, N.Y., a corporation of Delaware Filed Feb. 7, 1963, Ser. No.257,044 Claims priority, application Great Britain, June 26, 1962,24,502/ 62 '7 Claims. (Cl. 239-1323) The present invention relates to acombustion device for hydrocarbon fuel comprising a cup-shaped flamechamber adapted to be connected to a heating or reaction space or thelike, the bottom of the cup-shaped flame chamber having an opening forthe supply of fuel and an oxidizing medium, for instance, oxygen or air.

Combustion devices of this type are known and will be referred to ascombustion devices of the type specified. The combustion takes placeentirely or at least to a large extent inside the flame chamber, and thehot gases find their way into a heating or reaction space to which thedevice is connected. A very compact combustion or reaction zone isobtained by which a complete combustion of hydrocarbon material can beobtained without excess air and also complete or partial combustion maybe possible.

It is an object of the invention to provide a combustion device which isconstructed in such a way that a very high intensity reaction zone isformed and wherein the risk of damaging the walls of the flame chamberis minimized, and which is suitable to be applied in a process forproducing, by partial combustion of a hydrocarbon with anoxygen-containing gas, a product gas containing hydrogen and carbonmonoxide.

The combustion device according to the invent-ion can also beadvantageously used in combination with open hearth furnaces for meltingsteel.

Another object of the invention is to provide a system wherein the flamepattern and gas flow can be changed according to the relative positionsof specific constructional elements of the system.

According to the present invention, a combustion system of the typespecified is characterized by the combination of a water-cooled metalside wall containing an intermediate circular batfle terminating nearthe open end of the flame chamber and constituting two concentricannular cooling channels through which the cooling medium is enabled tocirculate, of a burner nozzle comprising an annular conical channel forthe fuel and oxygen or air, the diameter of the flame chamber beinglarger than and preferably at least 1.5 times and at most 6 times thediameter of the outlet of the annular conical channel, and of a flatmetal bottom of the flame chamber comprising a flat-faced centrallyarranged burner nozzle tip.

It has been found that the above-arrangements ensure that the metalparts of the system will be protected against excessive hightemperatures occurring Within the flame chamber during operation andthat simultaneously a stable combustion or conversion zone is obtainedas a result of the required relationship between the diameters of theoutlet of the annular conical channel and of the flame chamber,respectively. In particular, a specific gas flow pattern is created,with as the main feature an outer toroidal whirl of gases leading backheat to near the place where the reaction media issue from the annularopening, thus ensuring a stable reaction.

The side wall of the flame chamber is preferably adjustable in lengthbetween 0.1 and 0.8 of the diameter of the flame chamber.

nt it Patented Dec. 21, 1965 By moving the center portion axially withregard to the flame chamber wall the flame shape can be influenced atwill from an open toroidal form, corresponding with the above-mentionedshorter length of the chamber wall as a limit for ensuring that theouter whirl will at least be maintained during operation, to a closed,double toroidal form corresponding with the greater length of the flamechamber wall. The open toroidal flame shape is suitable to be used incases wherein the burner is connected to a heating or react-ion chamberin an oblique position, e.g., at 45, so that then during operation anequal distribution of the hot products from the burner over the chamberis ensured.

The diverging conical fuel supply channel may have a mouth cone anglelying between 30 and as outer allowable limits for ensuring asatisfactory operation of the system.

In the outer and/or inner wall of the conical annular channel one ormore supply openings for liquid fuel may be provided so as to introducefuel into and mix it with the oxygen or air stream; an additional axialchannel may also be present in a central barrel of the burner throughwhich, for instance, oxygen alone can be passed to provide oxygenlancing before burner shut down, or steam for the modification of apartial combustion process in which case the channel is preferably inthe form of a second inner divergently conical passage.

A combustion device in accordance with the present invention will now bedescribed by way of example with reference to the accompanying drawing,in which FIG. 1 shows a diagrammatic cross-section of the system and inwhich FIGS. 2 and 3 show, on a reduced scale, diagrammatic views insection of the system in two different positions of the flame chamberwall with the corresponding flame patterns occurring therein duringoperation.

As shown in the drawing, the system includes a cupshaped flame chamber 1in which combustion takes place, toroidal gas eddies being formed inoperation in the manner indicated diagrammatically by the arrows 2 and3. The cup-shaped flame chamber 1 is provided with a flat bottom 4, inwhich a burner with a flat nozzle 5 is centrally arranged. Between thenozzle 5 and the bottom part 4 a conical annular channel 6 is presentfor leading the fuel-oxidant mixture into the cup-shaped flame chamber 1between the toroidal gas streams 2 and 3. The side wall 7 of the flamechamber 1 is hollow and is provide-d with a circular baflle 8constituting two concentrical annular water cooling channels 9 and 10,these channels being in communication at the most forward end 11 of theside wall. Suitable inlet and outlets for water circulation are provided(not shown in the drawing), connected to the inner and outer coolingchannels 9, 10, respectively.

In preferred operation, air or oxygen is supplied through a tube 12;debouching into the annular conical channel 6. A supply for liquid fuelcomprises a channel 13 within a central barrel 14, which channel 13 isconnected to a slit-shaped opening 15 near the outlet of the channel 6.However, it is also possible to arrange the fuel supply in the outerwall of the channel 6 as, for example, by means of a supply channel 16and openings 17 in the outer wall of the channel 6. In this case thebarrel 14 is available for providing a supply channel for otherpurposes, as, for instance, for the supply of oxygen alone, to besupplied after a shut down of the apparatus. It is, of course, alsopossible to use a gaseous hydrocarbon fuel in which case the fuel may bepremixed with the air which is to be used for its combustion. Instead ofthe slit-shaped opening 15 a series of equally distributed separateopenings can be used.

In FIGS. 2 and 3, showing the particular flame patterns which occur atdifferent positions of the flame chamber wall, the wall as well as thebottom part of this chamber are not indicated as hollow members, for thesake of simplicity, but it should be noted that the detailed particularsof this embodiment are similar to those described with reference to FIG.1.

The present combustion device may also be provided with water supplymeans for the injection of water into the gas stream when it is intendedto produce hydrogen and carbon monoxide containing gas mixtures bypartial combustion of hydrocarbons with oxygen or air. Such means mayconsist of a number of small supply openings 18 arranged in a circle inthe bottom 4 of the cup-shaped flame chamber 1 around the channel 6.Alternatively, an annular slit in the inner or outer Wall of the channel6 may be provided for the above purpose. Such a slit can be suitablyarranged opposite the fuel supply opening. The water can be suppliedthrough a hollow space surrounding the tube 12, if desired. In thelatter case the water passing through said space, can additionally beused as cooling water.

Tests have been carried out with a system according to the invention,wherein it has been operated for preparing gas mixtures containinghydrogen and carbon monoxide by the partial combustion of hydrocarbonswith oxygen (air, and air enriched with oxygen may also be employed),which tests gave quite satisfactory results. Also as a high intensitycombustor, i.e. for complete combustion, the system has been proved towork satisfactorily.

The test apparatus concerned had the following main dimensions:

Inner diameter of the flame chamber (D inches 4 Diameter of the annualfuel supply (D inches 1% 2% Length of flame chamber wall (L) Cone offuel spray, degrees 50 5O 1 From inch to 2 inches in both cases.

form two concentric annular coolng channels through which a coolingmedium may circulate;

burner nozzle disposed in the center of the bottom wall of the flamechamber for supplying fuel and an oxidizing medium to the flame chamber,said burner nozzle comprising an annular diverging conical channelhaving a cone angle between 30 and said conical channel in additionhaving an outlet opening in the bottom wall of said flame chamber, saidburner nozzle in addition having a flat-faced tip;

the diameter of the flame chamber being larger than the diameter of theoutlet of said burner nozzle.

2. The combustion device according to claim 1, characterized in that thediameter of the flame chamber is at least 1.5 times and at most 6 timesthe diameter of the outlet of the annular conical channel.

3. The combustion device according to claim 1, characterized in that thelength of the cup-shaped flame chamber is adjustable.

4. The combustion device according to claim 3, characterized in that thelength of the flame-chamber is adjustable between 0.1 and 0.8 of thediameter of the flame chamber.

5. The combustion device according to claim 1, characterized in that atleast one of the outer and inner walls of the conical annular channel isprovided with one or more fuel supply openings.

6. The combustion device according to claim 1, characterized in that thebottom wall of the cup-shaped flame is provided with water supplyopenings.

7. The combustion device according to claim 1, characterized in that atleast one of the inner and outer walls of the annular conical channel isprovided with water supply openings.

References Cited by the Examiner UNITED STATES PATENTS 1,160,806 11/1915Wuestner et a1 1584.5 1,401,737 12/1921 Rumbarger. 1,702,731 2/ 1929Hymer. 2,430,396 11/1947 Gollin. 2,515,845 7/1950 Van den Bussche 151 16X 2,905,234 9/1959 Scholz.

FOREIGN PATENTS 680,057 8/1939 Germany.

219,378 7/1924 Great Britain.

821,856 10/1959 Great Britain.

FREDERICK L. MATTESON, JR., Primary Examiner.

MEYER PERLIN, Examiner.

1. A COMBUSTION DEVICE FOR HYDROCARBON FUEL COMPRISING: A CUP-SHAPEDFLAME CHAMBER ADAPTED TO BE CONNECTED TO A HEATING OR REACTION CHAMBER,SAID FLAME CHAMBER HAVING A GREATER DIAMETER THAN DEPTH AND ASUBSTANTIALLY FLAT BOTTOM WALL: SAID FLAME CHAMBER HAVING A HOLLOWLIQUID COOLED SIDEWALL INCLUDING AN INTERMEDIATE CIRCULAR BAFFLETERMINATING NEAR THE OPEN END OF THE FLAME CHAMBER TO FORM TWO CONCENTICANNULAR COOLING CHANNELS THROUGH WHICH A COOLING MEDIUM MAY CIRCULATE; ABURNER NOZZLE DISPOSED IN THE CENTER OF THE BOTTOM WALL OF THE FLAMECHAMBER FOR SUPPORTING FUEL AND AN OXIDIZING MEDIUM TO THE FLAMECHAMBER, SAID BURNER